Author Ken Follett, who has seen his bestsellers turned into films (“Eye of the Needle”) and television dramas, had one stipulation for anyone wanting to adapt his beloved 1989 novel “The Pillars of the Earth”: no stinginess when it came to air time.

“I’ve never made conditions with the other books, just sold the rights and left it to the filmmakers,” said the UK-born writer by phone recently. “But in this case, the story would be destroyed if it were reduced to four hours or two hours. That was a dealbreaker.”

A rollicking tale of passion, greed, and treachery among kings that’s set against the building of a cathedral in the fictional English town of Kingsbridge in the 12th century, the massive “Pillars,” which has sold more than 14 million copies, and was an Oprah’s Book Club selection, is now a Follett-approved, 8-hour miniseries on the pay cable channel Starz, premiering this Friday.

“I heaved a huge sigh of relief when I read it,” says Follett of John Pielmeier’s (“Agnes of God”) faithful, fast-paced script when it was sent to him a year and a half ago. “It really follows my story. It’s damn good.”

“Pillars” interweaves the tales of a mysterious female healer, an ambitious monk, a master builder, a feisty earl’s daughter, a power-mad churchman and countless others over decades of royal upheaval. Pielmeier describes the book’s enduring appeal this way: “It’s a book about reaching upward,” says the 61-year-old playwright and screenwriter. A former actor, Pielmeier also plays the monk Cuthbert in the mini-series, Pielmeier adds, “Whether you’re a religious person striving to touch God, or a humanist trying to better yourself, the building of the cathedral is a really important metaphor for us. Plus, it’s just a great yarn, and so well told.”

Casting was a bonanza. Prestige stalwarts Donald Sutherland as compassionate earl Bartholomew, “Deadwood” star Ian McShane as the cunning Bishop Waleran, and PBS stud Matthew McFadyen (“Pride & Prejudice”) as Prior Philip, are joined by talented up-and-comers such as Hayley Atwell (“The Duchess”) as Bartholomew’s daughter Aliena, and Tony Award winner Eddie Redmayne (“Red”) as Jack, the young artist who falls for her.

Acclaimed actor Rufus Sewell (“Eleventh Hour”) also heads up the cast as hard-working mason Tom Builder, the cathedral’s initial planner. When he was sent the script, Sewell — who has played his fair share of noblemen and royalty in period pieces — fought hard to play Tom.

“It wasn’t their idea,” says Sewell, 42. “But I was interested in playing a straightforward, intelligent working man. There’s something poetic about his soul, his spiritual connection to his work. Of course, if they’d offered it to me, I probably would have campaigned to play something else! They were all really fleshed-out roles.”

The character in “Pillars” that readers loved to hate has always been William Hamleigh, a ruthless aspirant to earldom who commits many vile acts. British actor David Oakes says that playing the role has its own odd rewards.

“If you look at all the good guys in this film, they get to kiss girls and look handsome,” says Oakes, 26. “But I got to fight with swords, set fire to people and I got to do it wearing leather, looking medieval with gruesome facial hair. I’m hoping I get some hate mail.”

One letter writer could be Oakes’ own father, a clergyman who bought the novel upon learning of his son’s casting, only to have it fall open to a page describing one of William’s more awful sins.

“He said, ‘Congratulations, but I’m not particularly keen that you’re playing that character,’” recalls Oakes, laughing. “He’s been fantastic, but he doesn’t know a lot of what I shot, so he might disown me afterwards.”

At least Oakes has a fan in Follett, who was pleased with the casting, even when a character’s book description didn’t jibe with the hiree. “Regan Hamleigh [William’s scheming mother] is an extraordinarily hideous woman in the book, with a face covered with boils,” says Follett, 61. “And they cast Sarah Parish, who is beautiful! But the producers said, ‘Put a hideous person on-screen for too long, and people will switch off.’ So I understand that.”

In the end, Follett’s comfort with the handling of “Pillars,” which was filmed over five months last year in Hungary and Austria, was such that he allowed the same creative team to option its sequel, “World Without End.” Pielmeier is busy at work adapting that book right now.

Says Follett, “If everybody loves ‘The Pillars of the Earth’ as much as we think they’re going to, then we’ll make the second one.”